After saying just a month ago that he would return for his senior season, a convergence of factors led the junior quarterback to change his mind.

It is clear the change of coaching staff was a hard pill for him to swallow. He had a close relationship with coordinator Noel Mazzone and had a firm grasp of the offensive game plan.

After the Las Vegas Bowl, Osweiler became teary-eyed as he spoke about no longer working with the coach.

"He's been everything to me and I love him," he said.

The wheels were in motion.

It took a bit for Osweiler to connect with new head coach Todd Graham. A planned meeting between the two was delayed, leaving the quarterback briefly miffed. But after they finally spoke, Osweiler felt comfortable with Graham's energy and approach and wasn't troubled by the discipline-fueled changes coming the team's way. He could see himself fitting in.

Comfortable is one thing. Being blown away and feeling enthusiastic about staying is another.

That wasn't there. If you want to fault Graham for something, that's it. Would Osweiler have stayed had, say, Urban Meyer, taken the job? Probably.

More significant is that Osweiler started taking a closer look at the offense around him. Three of ASU's top four receivers -- Gerell Robinson, Aaron Pflugrad and Mike Willie -- are gone. The offensive line will be a little less experienced.

While the Sun Devils have a lot of promising talent coming back, there is always fear of the unknown.

He wondered just how much he could he have improved his statistics from his junior season, when he threw for 4,036 yards, including 26 touchdowns and 13 interceptions, and completed 63.2 percent of his passes?

If Osweiler was convinced he could have put up big numbers in 2012, he would likely have stayed.

In last year's draft, former Washington quarterback Jake Locker, who was selected eighth overall by the Tennessee Titans, signed a four-year, $12.59 million deal. Meanwhile, third-round pick Ryan Mallett signed a four-year $2.2 million with New England and fifth-round pick Rick Stanzi did the same with the Kansas City Chiefs.

That's a $10 million difference. That's reason to stick around if you feel you could better your draft status.

Osweiler did request from the NFL information about where he would be projected and the response suggested somewhere from the third to fifth rounds. He was comfortable with that.

It will be interesting to see where Osweiler lands. Last year, four quarterbacks were taken among the first 12 picks, and then only three total in the next three rounds.

It helped Osweiler's decision along that two high-profile college quarterbacks --USC's Matt Barkley and Oklahoma's Landry Jones -- announced that they were staying in school. That thinned out the talent pool a bit.

And despite rumors to the contrary, Osweiler has told friends that he never seriously considered transferring to UCLA to join Mazzone, the Bruins' new offensive coordinator.

Mazzone, in fact, encouraged Osweiler to stay in school but told him he would help him prepare for the draft if he decided to go that route. Mazzone has worked with many quarterbacks in that capacity, including flavor-of-the-season Tim Tebow.

But Osweiler had made his decision. He saw opportunity, he saw money and he didn't see a big enough reason to come back. That might be painful for some ASU fans to hear, but the NFL is a gold-plated dangling carrot.

"Not a single day has gone by where I have had to second-guess or question my decision to enroll at ASU," Osweiler said. "I knew that in my heart that it was part of my destiny."

He made a classy exit.

The quote Osweiler uses on his Twitter page is from late British economist Walter Bagehot, who said, "The greatest pleasure in life is doing what people say you cannot do."